| SONG Jia-wei,WANG Xian-bin,JIANG Xin-ge,LIU Tai-kai,ZHANG Nan-nan,SONG Chen,DENG Chang-guang,DENG Chun-ming,LIU Min.The Preparation and Performance of Gradient Porous Electrodes Obtained via Atmospheric Plasma Spraying Used in Alkaline Water Electrolysis[J],51(11):423-435 |
| The Preparation and Performance of Gradient Porous Electrodes Obtained via Atmospheric Plasma Spraying Used in Alkaline Water Electrolysis |
| |
| View Full Text View/Add Comment Download reader |
| DOI：10.16490/j.cnki.issn.1001-3660.2022.11.040 |
| KeyWord:water electrolysis atmospheric plasma spraying gradient porosity three-dimensional microstructure electrochemical impedance spectrum |
| Author | Institution |
| SONG Jia-wei |
Department of Material Science and Engineering, Shenyang University of Technology, Shenyang , China;Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| WANG Xian-bin |
Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| JIANG Xin-ge |
Department of Material Science and Engineering, Shenyang University of Technology, Shenyang , China;Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| LIU Tai-kai |
Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| ZHANG Nan-nan |
Department of Material Science and Engineering, Shenyang University of Technology, Shenyang , China |
| SONG Chen |
Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| DENG Chang-guang |
Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| DENG Chun-ming |
Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
| LIU Min |
Institute of New Materials, Guangdong Academy of Science, National Engineering Laboratory for Modern Materials Surface Engineering Technology, Guangzhou , China |
|
| Hits: |
| Download times: |
| Abstract: |
| This paper aims to explore the effect of electrode structure on hydrogen evolution performance during alkaline water electrolysis. By preparing a gradient-arranged porous structure, the contradictory problems existing in the specific surface area and mass transfer and transport of a single porous structure can be effectively balanced, achieving a more optimistic hydrogen evolution effect. In this paper, spraying powders with Al content of 30vol%, 40vol% and 50vol% were obtained by mixing Ni powder and Al powder. Then four kinds of coating powders of N30A, N40A, N50A, and N543A were prepared by atmospheric plasma spraying with the prepared powders respectively, wherein the N543A coating was prepared by spraying N50A, N40A, and N30A powders in turn. After chemical etching, four groups of porous coatings were successfully obtained. The 2D and 3D microscopic morphology of the sample were characterized by SEM and industrial CT. EDS, XPS and XRD showed the element valence state and phase composition of the sample. The hydrogen evolution properties of the samples were investigated and compared by electrochemical test methods such as linear sweep voltammetry (LSV), cyclic sweep voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The experimental results show that the porosity of the coating can be effectively controlled by controlling the addition amount of Al, and a loose and porous electrode structure can be obtained; Through the coordinated spraying of multiple groups of powders, the preparation of the gradient porous structure was successfully achieved. All electrodes showed good stability with no obvious attenuation before and after the test. In terms of the reaction mechanism, the control steps of the hydrogen evolution rate of the prepared samples are all Volmer processes, that is, the adsorption and dissociation process of water molecules. The change of aluminum content and the construction of the gradient coating did not significantly change the reaction mechanism. N30A has the smoothest surface, showing the impedance characteristics closest to the capacitor, therefore its electrolytic performance is the worst; N40A shows similar impedance characteristics to N50A, but its overall porosity is lower, so its electrolytic performance is poor; At low current density, N50A and N543A showed very close electrolytic performance while N543A showed more superior electrolytic performance at high current density, Combined with the results of its three- dimensional structure analysis, it can be seen that the three-dimensional porosity of N50A is higher than that of N543A, and it can provide better exhaust capacity during electrolysis, but the corresponding surface area or active sites are reduced, resulting in a higher hydrogen evolution overpotential at a higher current density. Due to the porous structure of the N543A sample, the gas generated by electrolysis can be effectively extracted, so it still shows better electrolytic performance than N50A when the porosity is lower than that of N50A. The introduction of the gradient porous structure can not only promote the transport of the electrolyte, but also provide better exhaust capacity and ensure sufficient reactive sites, so it can effectively improve the hydrogen evolution performance. |
| Close |
|
|
|